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1.
J Nutr Health Aging ; 21(7): 759-765, 2017.
Article in English | MEDLINE | ID: mdl-28717805

ABSTRACT

OBJECTIVES: To identify the relationship between diet-related indicators and overweight and obesity in older adults in rural Japan. DESIGN: Cross-sectional survey. SETTING: Obira, Hokkaido, Japan. PARTICIPANTS: Local residents aged between 65 and 74 years, except for those with poor health, were included. INTERVENTION: A health- and diet-related questionnaire was applied to participants house-to-house by trained health professionals. MEASUREMENTS: The following indicators were examined: number of meals, number of balanced meals, food diversity, food group diversity, chewing ability, alcohol intake habit, smoking habit, instrumental activities of daily living scores, age, and residing alone or with family. RESULTS: Of 550 residents, 317 residents completely responded to the questionnaire. Of these, 41 were had low body mass index (BMI≤20) and were excluded. This resulted in a sample of 307 subjects comprising 117 men and 190 women; 37.6% and 46.8% of men and women were classified as obese (BMI≥25), respectively. Women with a normal BMI (20

Subject(s)
Diet , Obesity/epidemiology , Overweight/epidemiology , Rural Population , Activities of Daily Living , Aged , Body Mass Index , Cross-Sectional Studies , Female , Humans , Japan , Life Style , Logistic Models , Male , Meals , Obesity/prevention & control , Overweight/prevention & control , Surveys and Questionnaires
2.
J Pept Sci ; 22(6): 406-14, 2016 Jun.
Article in English | MEDLINE | ID: mdl-27282137

ABSTRACT

Kisspeptin analogues with improved metabolic stability may represent important ligands in the study of the kisspeptin/KISS1R system and have therapeutic potential. In this paper we assess the activity of known and novel kisspeptin analogues utilising a dual luciferase reporter assay in KISS1R-transfected HEK293T cells. In general terms the results reflect the outcomes of other assay formats and a number of potent agonists were identified among the analogues, including ß(2) -hTyr-modified and fluorescently labelled forms. We also showed, by assaying kisspeptin in the presence of protease inhibitors, that proteolysis of kisspeptin activity within the reporter assay itself may diminish the agonist outputs. Copyright © 2016 European Peptide Society and John Wiley & Sons, Ltd.


Subject(s)
Amino Acids/chemistry , Kisspeptins/agonists , Receptors, G-Protein-Coupled/metabolism , Fluorescent Dyes/chemistry , HEK293 Cells , Humans , Ligands , Receptors, G-Protein-Coupled/chemistry , Receptors, Kisspeptin-1
3.
Neuroscience ; 294: 109-15, 2015 May 21.
Article in English | MEDLINE | ID: mdl-25772790

ABSTRACT

Serotonin (5-HT) is a key regulator of mood and sexual behaviors. 5-HT reuptake inhibitors have been used as antidepressants. Really interesting new gene (RING) finger proteins have been associated with 5-HT regulation but their role remains largely unknown. Some RING finger proteins are involved in the serotonergic system, therefore, we speculate that the gene expression of RING finger protein38 (rnf38) is regulated by the serotonergic system. In the present study, we aimed to identify the full length sequence of medaka (Oryzias latipes) rnf38 mRNA and investigate its association with the serotonergic system using an antidepressant, citalopram (CIT). We identified the full length rnf38 cDNA, which consisted of 2726 nucleotides spanning 12 exons and the deduced protein sequence consisting of 518 amino acid residues including a RING finger domain, a KIT motif and a coiled-coil domain. Medaka exposed to 10(-7)M of CIT showed anxiety-like behavior. The expressions of 5-HT-related genes, pet1, solute carrier family 6, member 4A (slc6a4) and tryptophan hydroxylase (tph2) were significantly low (P<0.05) in the hindbrain. On the other hand, rnf38 gene was significantly high (P<0.05) in the telencephalon and the hypothalamus. This shows that 5-HT synthesis and transport in the hindbrain is suppressed by CIT, which induces rnf38 gene expression in the forebrain where 5-HT neurons project. Thus, the expression of rnf38 is negatively regulated by the serotonergic system.


Subject(s)
Brain/metabolism , Carrier Proteins/metabolism , Neurons/metabolism , Serotonin/metabolism , Animals , Carrier Proteins/genetics , Citalopram/pharmacology , Cloning, Molecular/methods , Gene Expression/physiology , Male , Oryzias , RNA, Messenger , Tryptophan Hydroxylase/metabolism , Zinc Fingers
5.
Rev Sci Instrum ; 85(8): 086105, 2014 Aug.
Article in English | MEDLINE | ID: mdl-25173330

ABSTRACT

The absolute detection efficiency of a tapered microchannel plate with an open-area ratio of 90% was measured for Ne(+) with energies up to 5 keV, and comparison with the results for Xe(+) was made. As in the case of Xe(+), the maximum detection efficiency was 90%. The energy dependence of the efficiency curves normalized with respect to the open-area ratios was examined based on the scaling law proposed previously.

7.
Rev Sci Instrum ; 84(1): 014701, 2013 Jan.
Article in English | MEDLINE | ID: mdl-23387673

ABSTRACT

An eddy current testing (ECT) system using a high sensitive anisotropic magnetoresistive (AMR) sensor was developed. In this system, a 20 turn circular coil with a diameter of 3 mm was used to produce the excitation field. A high sensitivity AMR sensor was used to measure the magnetic field produced by the induced eddy currents. A specimen made of copper alloy was prepared to simulate the combustion chamber of liquid rocket. Scanning was realized by rotating the chamber with a motor. To reduce the influence of liftoff variance during scanning, a dual frequency excitation method was used. The experimental results proved that ECT system with an AMR sensor could be used to check liquid rocket combustion chamber.

9.
J Oral Rehabil ; 39(8): 568-75, 2012 Aug.
Article in English | MEDLINE | ID: mdl-22506492

ABSTRACT

Increasing need for long-term care in older adults is expected with the ageing of Japan's population. The aim of the present study was to show the relationship between perceived chewing ability and long-term care needs for over 5 years in elderly persons. The chewing ability of 812 elderly persons living independently was evaluated at baseline using self-assessed masticatory ability, and it was classified into one of three categories: ability to chew all foods (good masticatory ability), ability to chew only slightly hard food (fair masticatory ability), and ability to only chew soft or pureed food (poor masticatory ability). Participants' care needs were then followed through Japan's long-term care insurance system for over 5 years. The log-rank test and Cox proportional hazard model were used to examine statistical differences in the frequency of care-needs certification between participants with good and fair or poor masticatory ability. Among participants aged 65-79 years, the frequency of care-needs certification was significantly higher in those with fair or poor masticatory ability than in those with good masticatory ability, and the relative hazard ratio was significantly higher in those with fair or poor masticatory ability than in those with good masticatory ability, after adjusting for age, gender, current employment status, educational background, social interaction, chronic medical conditions and dentition status. These relationships were not found among those aged 80-93 years. Impairment in perceived chewing ability may be associated with higher incidence of certification in Japan's long-term care insurance system among elderly persons aged 65-79.


Subject(s)
Long-Term Care/statistics & numerical data , Mastication/physiology , Aged , Aged, 80 and over , Female , Follow-Up Studies , Humans , Insurance, Long-Term Care/statistics & numerical data , Male , Rural Health , Self Report , Self-Assessment
10.
Community Dent Health ; 29(1): 39-44, 2012 Mar.
Article in English | MEDLINE | ID: mdl-22482248

ABSTRACT

UNLABELLED: Self-assessed masticatory ability has been shown to be significantly related to general health among elderly persons. OBJECTIVE: To identify oral factors associated with the self-assessed masticatory ability. BASIC RESEARCH DESIGN: Cross-sectional study. PARTICIPANTS: A total of 736 community-dwelling elderly persons. MAIN OUTCOME MEASURES: Data on background factors and the self-assessed masticatory ability were collected by questionnaire. An intraoral examination examined the pattern of posterior occluding pairs of natural teeth (POPs), the WHO Community Periodontal Index of Treatment Needs (CPI) and denture-related factors such as use of dentures, pain when using dentures and stability and retention of dentures. Chi-squared tests examined the relationships between the self-assessed masticatory ability and the background factors and oral conditions. Ordinal regression models were constructed with the self-assessed masticatory ability as the dependent variable and oral conditions as the principal independent variables, to adjust for the potential confounding variables. RESULTS: Self-assessed impairment of masticatory ability was associated with lost POPs (p < 0.001) and CPI (p = 0.012). In the participants with lost POPs, self-assessed impairment of masticatory ability was associated with not using dentures and pain when using dentures (p < 0.001). In the totally edentulous subjects, impairment of masticatory ability was not associated with stability and retention of dentures (p = 0.070). CONCLUSIONS: Factors affecting self-assessed masticatory ability include the pattern of POPs, periodontal status, denture use and pain when using dentures.


Subject(s)
Independent Living , Mastication/physiology , Aged , Aged, 80 and over , Bicuspid/pathology , Chronic Disease , Cross-Sectional Studies , Denture Retention , Dentures , Educational Status , Employment , Family Characteristics , Female , Health Status , Humans , Jaw, Edentulous/classification , Jaw, Edentulous, Partially/classification , Male , Molar/pathology , Periodontal Index , Self-Assessment , Social Participation , Surveys and Questionnaires
11.
Cell Death Differ ; 19(1): 170-9, 2012 Jan.
Article in English | MEDLINE | ID: mdl-21681193

ABSTRACT

Prostate cancers generally become androgen-independent and resistant to hormone therapy with progression. To understand the underlying mechanisms and facilitate the development of novel treatments for androgen-independent prostate cancer, we have investigated plasma membrane-associated sialidase (NEU3), the key enzyme for ganglioside hydrolysis participating in transmembrane signaling. We have discovered NEU3 to be upregulated in human prostate cancer compared with non-cancerous tissue, correlating with the Gleason score. NEU3 silencing with siRNA in prostate cancer PC-3 and LNCaP cells resulted in increased expression of differentiation markers and in cell apoptosis, but decrease in Bcl-2 as well as a progression-related transcription factor, early growth response gene (EGR-1). In androgen-sensitive LNCaP cells, forced overexpression of NEU3 significantly induced expression of EGR-1, androgen receptor (AR) and PSA both with and without androgen, the cells becoming sensitive to androgen. The NEU3-mediated induction was abrogated by inhibitors for PI-3 kinase and MAP kinase and more specifically by their silencing in the absence of androgen, being confirmed by increased phosphorylation of AKT and ERK1/2 in NEU3 overexpressing cells. NEU3 siRNA introduction caused reduction of cell growth of an androgen-independent PC-3 cells in culture and of transplanted tumors in nude mice. These data suggest that NEU3 regulates tumor progression through AR signaling, and thus be a potential tool for diagnosis and therapy of androgen-independent prostate cancer.


Subject(s)
Androgens/metabolism , Membrane Proteins/metabolism , Neuraminidase/metabolism , Prostatic Neoplasms/pathology , Receptors, Androgen/metabolism , Animals , Apoptosis , Cell Differentiation , Cell Line, Tumor , Disease Progression , Early Growth Response Transcription Factors/metabolism , Gene Silencing , Humans , MAP Kinase Signaling System , Male , Membrane Proteins/genetics , Mice , Mice, Nude , Neuraminidase/genetics , Phosphorylation , Prostate-Specific Antigen/metabolism , Prostatic Neoplasms/metabolism , RNA, Small Interfering/genetics , Receptors, Androgen/genetics , Signal Transduction
12.
J Oral Rehabil ; 38(9): 674-9, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21342214

ABSTRACT

The aim of the present study was to elucidate whether self-assessed masticatory ability (masticatory ability) is significantly related to muscle strength of the body evaluated as handgrip strength and skeletal muscle mass of the whole body (kg) (SMM) after adjusting for confounding variables, including, age, gender, height, weight, employment status, type of household, educational background, social interaction, chronic medical conditions, smoking habit, drinking habits and dentition status among the elderly. A total of 381 persons aged 67-74 years were enrolled. Masticatory ability was classified into one of three categories: ability to chew all kinds of food, ability to chew only slightly hard food or ability to chew only soft or pureed food. Handgrip strength was measured, and bioimpedance analysis was used to estimate SMM. One-way analysis of variance and Bonferroni methods were used to examine differences in handgrip strength and SMM among the three groups of masticatory ability. An ordinal regression model was conducted with masticatory ability as the dependent variable and handgrip strength as the principal independent variable. Handgrip strength was significantly lower in those individuals who could chew only soft or pureed food than in those individuals who could chew all kinds of food. No significant difference in SMM was found among the three groups of masticatory ability. Masticatory ability was significantly related to handgrip strength after adjusting for SMM, dentition status and background factors. Chewing ability may be related to muscle strength of the body evaluated as handgrip strength, but not evaluated as SMM.


Subject(s)
Hand Strength/physiology , Mastication/physiology , Muscle, Skeletal/physiology , Aged , Cross-Sectional Studies , Female , Food , Humans , Japan , Male , Self-Assessment
13.
J Oral Rehabil ; 38(5): 321-7, 2011 May.
Article in English | MEDLINE | ID: mdl-21029149

ABSTRACT

The escalating medical costs are a social problem in many countries. Masticatory ability is thought to be related to the general health conditions. The purpose of this study was to show relationships between self-assessed masticatory ability and medical costs among the elderly living independently in community. Data on background factors and self-assessed masticatory ability were collected from 702 Japanese elderly persons by questionnaires. An intra-oral examination was performed to examine the number of remaining teeth. Self-assessed masticatory ability was classified into one of three categories: ability to chew all kinds of food (Good), ability to chew only slightly hard food (Fair) or ability to chew only soft or pureed food (Poor). Data on the annual medical excluding dental costs were obtained from the Japanese National Health Insurance system. The Kruskal-Wallis test was used to examine differences in outpatient costs and hospitalisation costs among the three groups of self-assessed masticatory ability. Univariate unconditional logistic regression models and multivariate logistic regression models were used with medical costs as the dependent variable and self-assessed masticatory ability as the principal independent variable. A significant difference (P=0·039) in hospitalisation costs but not outpatient costs was found among the three groups of self-assessed masticatory ability. The multivariate logistic regression analysis showed that severely impaired masticatory ability (Poor) was significantly related to higher costs of hospitalisation. Self-assessed impairment of masticatory ability may be a significant and independent indicator of higher costs of hospitalisation among community-dwelling elderly persons.


Subject(s)
Health Care Costs/statistics & numerical data , Hospital Costs/statistics & numerical data , Hospitalization/economics , Mastication , Aged , Aged, 80 and over , Ambulatory Care/economics , Female , Humans , Independent Living , Japan , Logistic Models , Male , National Health Programs/economics , Self-Assessment , Statistics, Nonparametric , Surveys and Questionnaires
14.
Clin Exp Immunol ; 161(2): 233-41, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20491786

ABSTRACT

CD44 is a highly glycosylated cell adhesion molecule that is involved in lymphocyte infiltration of inflamed tissues. We have demonstrated previously that sialic acid residues of CD44 negatively regulates its receptor function and CD44 plays an important role in the accumulation of T helper type 2 (Th2) cells in the airway of a murine model of acute asthma. Here we evaluated the role of sialidase in the hyaluronic acid (HA) receptor function of CD44 expressed on CD4+ T cells, as well as in the development of a mite antigen-induced murine model of acute asthma. Splenic CD4+ T cell binding of HA was examined with flow cytometry. Expression of sialidases (Neu1, Neu2, Neu3 and Neu4) in spleen cells was evaluated by quantitative real-time reverse transcription-polymerase chain reaction. Airway inflammation and airway hyperresponsiveness (AHR) were evaluated in the asthmatic Neu1-deficient mouse strain SM/J model. Splenic CD4+ T cells from asthmatic model mice displayed increased HA receptor activity of CD44 after culture with the antigen, along with characteristic parallel induction of sialidase (Neu1) expression. This induction of HA binding was suppressed significantly by a sialidase inhibitor and was not observed in SM/J mice. Th2 cytokine concentration and absolute number of Th2 cells in the bronchoalveolar lavage fluid, and AHR were decreased in SM/J mice. In conclusion, HA receptor activity of CD44 and acute asthmatic reactions, including Th2-mediated airway inflammation and AHR, are dependent upon Neu1 enzymatic activity. Our observation suggests that Neu1 may be a target molecule for the treatment of asthma.


Subject(s)
Asthma/immunology , Asthma/physiopathology , Hyaluronan Receptors/metabolism , Neuraminidase/metabolism , Th2 Cells/immunology , Th2 Cells/metabolism , Animals , Antigens, Dermatophagoides/immunology , Asthma/genetics , Azides/pharmacology , Bronchial Hyperreactivity/immunology , Bronchial Hyperreactivity/physiopathology , Bronchoalveolar Lavage Fluid/cytology , Bronchoalveolar Lavage Fluid/immunology , CD4-Positive T-Lymphocytes/drug effects , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/metabolism , Cell Count , Chemokine CCL11/metabolism , Enzyme Inhibitors/pharmacology , Eosinophils/cytology , Eosinophils/immunology , Female , Gene Expression/drug effects , Gene Expression/genetics , Gene Expression/immunology , Hyaluronic Acid/metabolism , Inflammation/immunology , Inflammation/pathology , Interferon-gamma/metabolism , Interleukins/metabolism , Lymph Nodes/cytology , Lymph Nodes/immunology , Lymphocyte Activation/immunology , Mice , Mice, Inbred BALB C , Mice, Inbred DBA , Mice, Mutant Strains , Neuraminidase/antagonists & inhibitors , Neuraminidase/genetics , Neuraminidase/pharmacology , Peanut Agglutinin/metabolism , Sialic Acids/pharmacology , Spleen/cytology , Spleen/enzymology , Spleen/immunology , Th1 Cells/cytology , Th1 Cells/immunology , Th1 Cells/metabolism , Th2 Cells/cytology , Vaccination
15.
Mol Microbiol ; 76(3): 634-47, 2010 May.
Article in English | MEDLINE | ID: mdl-20199598

ABSTRACT

Although division site positioning in rod-shaped bacteria is generally believed to occur through the combined effect of nucleoid occlusion and the Min system, several lines of evidence suggest the existence of additional mechanisms. Studies using outgrown spores of Bacillus subtilis have shown that inhibiting the early stages of DNA replication, leading up to assembly of the replisome at oriC, influences Z ring positioning. Here we examine whether Z ring formation at midcell under various conditions of DNA replication inhibition is solely the result of relief of nucleoid occlusion. We show that midcell Z rings form preferentially over unreplicated nucleoids that have a bilobed morphology (lowering DNA concentration at midcell), whereas acentral Z rings form beside a single-lobed nucleoid. Remarkably however, when the DnaB replication initiation protein is inactivated midcell Z rings never form over bilobed nucleoids. Relieving nucleoid occlusion by deleting noc increased midcell Z ring frequency for all situations of DNA replication inhibition, however not to the same extent, with the DnaB-inactivated strain having the lowest frequency of midcell Z rings. We propose an additional mechanism for Z ring positioning in which the division site becomes increasingly potentiated for Z ring formation as initiation of replication is progressively completed.


Subject(s)
Bacillus subtilis/cytology , Bacillus subtilis/genetics , Cell Division , Cell Nucleolus/genetics , DNA Replication , Bacillus subtilis/metabolism , Bacterial Proteins , Cell Nucleolus/metabolism , Intranuclear Inclusion Bodies/genetics , Intranuclear Inclusion Bodies/metabolism
16.
Acta Radiol ; 50(5): 507-11, 2009 Jun.
Article in English | MEDLINE | ID: mdl-19353344

ABSTRACT

BACKGROUND: The three-dimensional double-echo steady-state (3D-DESS) sequence is being used to investigate sequence parameters for the assessment of knee cartilage by magnetic resonance imaging (MRI). With the flip angle (FA) values that are commonly used, contrast between cartilage and synovial fluid may be too low to delineate minor lesions of the cartilage surface. PURPOSE: To investigate the value of FA maximizing contrast between cartilage and synovial fluid using the 3D-DESS sequence. MATERIAL AND METHODS: In 10 healthy volunteers (five men, five women; age range 23-48 years), 3D-DESS imaging was performed to capture median sagittal sections of the knee by adjusting FA from 10 degrees to 90 degrees. Cartilage-synovial fluid contrast-to-noise ratio (CNR) was measured to determine the value of FA maximizing CNR. Water-excitation pulse was used to suppress fat signals. MRI was performed at 1.0 T using a circular polarization flex coil. RESULTS: Cartilage-synovial fluid CNR was highest with 90 degrees FA, yielding images with good contrast between cartilage and synovial fluid. CONCLUSION: Simply by increasing FA to 90 degrees in 3D-DESS imaging, the contrast between cartilage and synovial fluid increased substantially. Subtle cartilage lesions may thus be detectable using 3D-DESS sequences.


Subject(s)
Image Enhancement/methods , Imaging, Three-Dimensional/methods , Knee/anatomy & histology , Magnetic Resonance Imaging/methods , Adult , Female , Humans , Male , Middle Aged , Reference Values , Young Adult
17.
Int J Gynecol Cancer ; 18(6): 1300-4, 2008.
Article in English | MEDLINE | ID: mdl-18284451

ABSTRACT

Cisplatin and ifosfamide are considered among the most active drugs in both neoadjuvant and salvage treatments for patients with cervical cancer. Nedaplatin is an analog of cisplatin and it exhibits lesser nephrotoxicity, neurotoxicity, and gastrointestinal toxicity than cisplatin. This study aimed to determine the recommended dosage of nedaplatin plus ifosfamide chemoradiotherapy for advanced squamous cell carcinoma (SCC) of the uterine cervix. Beginning with a dose of 65 mg/m(2), nedaplatin (day 1) combined with ifosfamide 1 g/m(2) (days 1-5) was designed to be administered for three cycles (minimum: two cycles); its dose was gradually escalated up to 80 mg/m(2). Dose-limiting toxicity (DLT) was defined as a more than 7-day delay in the planned radiation therapy and/or planned chemotherapy (prior to the completion of two cycles) due to toxicity. Chemotherapy was not interrupted prior to the completion of two cycles in any patients. Of the 12 patients, 11 received three cycles of chemotherapy. DLT did not occur in any patient. We confirmed a clinical complete response (CR) in ten and partial response (PR) in two patients. The median follow-up period was 39 months (range: 18-57 months). Ten patients (83%) were alive and disease free, one patient was alive with disease, and only one patient died due to the disease. Nedaplatin and ifosfamide combination chemotherapy is a feasible and active chemoradiation strategy for patients with advanced SCC of the uterine cervix. With the ifosfamide dose fixed to 1 g/m(2), the recommended nedaplatin dosage was determined to be 80 mg/m(2) to be administered for three cycles.


Subject(s)
Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Carcinoma, Squamous Cell/drug therapy , Carcinoma, Squamous Cell/radiotherapy , Ifosfamide/therapeutic use , Organoplatinum Compounds/therapeutic use , Uterine Cervical Neoplasms/drug therapy , Uterine Cervical Neoplasms/radiotherapy , Adult , Aged , Antineoplastic Combined Chemotherapy Protocols/administration & dosage , Carcinoma, Squamous Cell/pathology , Combined Modality Therapy/adverse effects , Dose-Response Relationship, Drug , Female , Humans , Ifosfamide/administration & dosage , Middle Aged , Neoplasm Staging , Organoplatinum Compounds/administration & dosage , Uterine Cervical Neoplasms/pathology
18.
Environ Entomol ; 36(4): 871-7, 2007 Aug.
Article in English | MEDLINE | ID: mdl-17716478

ABSTRACT

The nymphal locomotion ability (walking distance) of the stenophagous bean bug Riptortus pedestris (Fabricius) was studied in each instar. We measured the walking distance using two systems. The walking distance in photophase was measured for 6 h using a tracking system with a charge coupled device (CCD) camera and computer software. The daily activity of nymphs was measured by an actograph system counting the number of infrared beam intercepts. The actograph data were converted to distance using a linear regression against the data of the tracking system. The longevity of nymphs without food was also studied to estimate the potential walking distance. Using both the tracking and actograph systems, it was determined that first instars walked less than the other instars (only 10.7 m within 6 h). The second to fifth instars could move 20-25 m within 6 h, and this distance did not differ among instar. This indicates that first instars seldom move after hatching in the field. The walking distance for 24 h varied and was greatest for the third instars (80.8 m). The potential longevity of nymphs was found to increase with instar age. Potential locomotion ability (walking distance for 24 hxpotential longevity) was high in the third to fifth instars (approximately 340 m). The potential locomotion ability for the second instars was relatively low compared with the elder instars (approximately 180 m). From these results, nymphs of R. pedestris seem to adapt by identifying feeding site locations after hatching and elder instars may be able to find a novel feeding site after the degradation of previous habitat.


Subject(s)
Heteroptera/physiology , Locomotion/physiology , Animals , Feeding Behavior , Longevity , Motor Activity/physiology , Nymph/physiology
19.
Oncogene ; 26(17): 2483-90, 2007 Apr 12.
Article in English | MEDLINE | ID: mdl-17334392

ABSTRACT

Human plasma membrane-associated sialidase (NEU3), a key enzyme for ganglioside degradation, is markedly upregulated in human cancers, leading to apoptosis suppression. To define molecular mechanisms and the possible target for NEU3, its encoding gene was silenced by small interference RNA (siRNA) or overexpressed in human cells. NEU3 siRNA-induced apoptosis with no special stimuli in HeLa cells, accompanied with decreased Bcl-xL and increased mda7 and GM3 synthase mRNA levels, whereas overexpression resulted in the opposite. Carcinoma HT-29 and MCF-7 cells appeared to be similarly affected, but normal cell lines demonstrated no significant changes. NEU3 siRNA was found to inhibit and NEU3 overexpression to stimulate Ras activation with consequent influence on extracellular signal-regulated kinases and Akt. Ras activation by NEU3 was abrogated by PP2 (src inhibitor) or AG1478 (epidermal growth factor receptor (EGFR) inhibitor), and NEU3 actually enhanced EGF-stimulated tyrosine-phosphorylation of EGFR, suggesting that the upstream targets might be tyrosine kinases including src and EGFR, and the subsequent stimulation of Ras cascade leads to the inhibition of cell apoptosis. Glycolipid changes observed seemed to be one of the causes of the cell effects. NEU3 may thus be an essential gene for cancer cell survival and siRNAs targeting this protein could have utility for gene-based therapy of human cancers.


Subject(s)
Cell Membrane/enzymology , Cell Membrane/pathology , Cell Transformation, Neoplastic/pathology , Neuraminidase/physiology , Apoptosis/genetics , Cell Line , Cell Membrane/genetics , Cell Survival/genetics , Cell Transformation, Neoplastic/genetics , Cell Transformation, Neoplastic/metabolism , Gene Silencing , HT29 Cells , HeLa Cells , Humans , Neuraminidase/antagonists & inhibitors , Neuraminidase/genetics , RNA Interference , RNA, Small Interfering/physiology , RNA, Small Interfering/therapeutic use
20.
Mol Ecol ; 15(2): 505-16, 2006 Feb.
Article in English | MEDLINE | ID: mdl-16448416

ABSTRACT

The fungus-growing termites Macrotermes cultivate the obligate ectosymbiontic fungi, Termitomyces. While their relationship has been extesively studied, little is known about the gut bacterial symbionts, which also presumably play a crucial role for the nutrition of the termite host. In this study, we investigated the bacterial gut microbiota in two colonies of Macrotermes gilvus, and compared the diversity and community structure of bacteria among nine termite morphotypes, differing in caste and/or age, using terminal restriction fragment length polymorphism (T-RFLP) and clonal analysis of 16S rRNA. The obtained molecular community profiles clustered by termite morphotype rather than by colony, and the clustering pattern was clearly more related to a difference in age than to caste. Thus, we suggest that the bacterial gut microbiota change in relation to the food of the termite, which comprises fallen leaves and the fungus nodules of Termitomyces in young workers, and leaves degraded by the fungi, in old workers. Despite these intracolony variations in bacterial gut microbiota, their T-RFLP profiles formed a distinct cluster against those of the fungus garden, adjacent soil and guts of sympatric wood-feeding termites, implying a consistency and uniqueness of gut microbiota in M. gilvus. Since many bacterial phylotypes from M. gilvus formed monophyletic clusters with those from distantly related termite species, we suggest that gut bacteria have co-evolved with the termite host and form a microbiota specific to a termite taxonomic and/or feeding group, and furthermore, to caste and age within a termite species.


Subject(s)
Bacteria/genetics , Gastrointestinal Tract/microbiology , Genetic Variation , Isoptera/microbiology , Isoptera/physiology , Age Factors , Animals , Bacteria/isolation & purification , Basidiomycota/physiology , Behavior, Animal/physiology , Phylogeny , Polymorphism, Restriction Fragment Length , RNA, Ribosomal, 16S
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